"Offshore geophysical surveys led to
their discovery, and earthquakes may have been
responsible for their demise," he adds.

Nur will moderate a special session about the
Menouthis/Herakleion discoveries on Monday, Dec.
18, at 8:30 a.m. at the fall meeting of the
American Geophysical Union in San Francisco.

Among the researchers scheduled to attend the
half-day session is Franck Goddio, the French
marine archaeologist who last June announced the
discovery of the submerged cities in the Bay of
Aboukir about 15 miles (25 kilometers) east of
Alexandria, Egypt.

Goddio and his divers made headlines when they
unearthed from the bottom of the Mediterranean
Sea giant marble statues and fractured columns ­
some dating back to the time of the pharaohs.

"In the ancient world, a major center of
various religions and cults existed here,"
says Goddio, director of the European Institute
of Submarine Archaeology in Paris.

"Numerous sources of ancient literature
verify the existence of the once famous
region," he adds, noting that some authors
described Herakleion and its sister city,
Menouthis, as opulent and decadent.

"These cities were not only renowned for
their riches and lifestyle, but also for their
many temples dedicated to the gods Serapis, Isis
and Anubis," says Goddio.

"Among others, the Greek historian
Herodotus described a temple of Hercules in
Herakleion, which he visited during the journey
through Egypt he began in 450 B.C.," he
adds.

The search for the missing cities began in
1996 -- a challenging task, recalls Goddio,
because it required surveying a 100-square-mile
area of the Mediterranean.

"We recognized that the work would be
only successfully achieved if a team gathered
from diverse disciplines could be formed,"
Goddio says, so he and the Egyptian Supreme
Council for Antiquities assembled specialists in
geophysics, archaeology, history and marine
diving to find evidence of the vanished
metropolises.

"The scientists only had one day left
aboard the ship when they finally discovered
Herakleion submerged in silt less than 24 feet [8
meters] below the sea surface," according to
Nur.

What caused these great cities to collapse and
sink?

A likely answer is earthquakes.

"In Alexandria itself," writes Nur,
"both historical records and archaeological
evidence of collapse have shown that the city was
devastated both onshore and offshore by an
earthquake in the mid- to late-eighth century
A.D., and by one or two earlier earthquakes
sometime during the period 200 to 600 A.D."

He points to rows of columns that all fell in
the same direction ­ strong evidence that a
devastating earthquake struck the Alexandria
region.

The sinking of the cities is more difficult to
explain, Nur concedes, but he says land may have
subsided as a result of earthquake-induced
liquefaction of the sea floor, or by tsunamis --
giant walls of water that sometimes sweep across
the shoreline in the aftermath of a marine
earthquake.

The Smithsonian Institution's Daniel J.
Stanley, a specialist on the geology of the Nile
River Delta, also will address the Dec. 18 AGU
session. He points out that Herakleion --
originally a shipping port at the mouth of the
Nile ­ may have been destroyed and flooded after
a branch of the river abruptly shifted course
during the first millennium.

However, Jean Yoyette of the College de France
in Paris will argue against the earthquake
theory, noting that some ancient texts say
nothing about major tectonic activity having
occurred in the region 1,500 years ago.

"Because the historical and
archaeological information in this region is so
sparse and incomplete," says Nur, "it
is not possible as yet to identify the earthquake
faults that devastated Alexandria and
Aboukir."

However, he will discuss three likely
locations of the fault system when he addresses
the AGU.

"The case of Alexandria and Aboukir
highlight the emerging importance of
archaeological information in general in helping
to predict earthquakes," Nur adds, noting
that other densely populated coastal regions
around the world face similar earthquake hazards
today.

A one-hour television special about the
expedition to Egypt will premiere on the
Discovery Channel USA on Jan. 29, 2001, at 9 p.m.
(ET/PT). The documentary, called "Ancient
Earthquakes, Sunken Cities," was filmed on
location and features Goddio, Stanley and Nur.

Betacam video clips and photographs from the
film will be available during a press conference
on Sunday, Dec. 17, at 2 p.m.

Photographs of the sunken cities expedition
will be available from Beth Foster at the
Discovery Channel. Call (301) 771-4108 or e-mail
her at Beth_Foster@discovery.com.